AY-227

Purdue University

Cooperative Extension Service

West Lafayette, IN 47907

Sunflower Production in Indiana--
Questions and Answers

Marvin L. Swearingin, Department of Agronomy

1. What types of sunflower are grown in the U.S.?

The two basic types of sunflower varieties grown are: 1) the oil
seed type and 2) non-oil types, which supply the birdfood and
confectionery market.

The oil seed type generally has small black seeds with a thin hull
which tends to adhere to the kernel. The seed contains 38 to 50
percent oil and about 20 percent protein. Thus, sun oil is the
primary-product and sun meal is a secondary product. Bushel weight of the
oil seed type is 28 to 30 pounds. Purchasers and processors usually
pay a premium over 40 percent oil and discount seed lots under 40
percent. An analysis for oil content is made of each sale before
payment is made.

The non-oil or confectionary types of sunflower has larger seed
with a thicker hull that is loosely attached to the kernel and more
easily removed. They have a lower oil content and test weight.

2. Where is sunflower produced?

Sunflower is widely grown in the world where the climate is not
favorable for soybean production. Russia, Romania, and Argentina are
large producers. Sunflower is the most important oil seed crop in
Europe and second only to soybean as an oil seed crop worldwide.

In the United States, the crop traditionally has been grown on the
northern and western fringes of the Corn Belt where corn and soybeans
have not performed well because of either a short growing season or
lack of rainfall. The four states, North Dakota, South Dakota,
Minnesota, and Texas, account for virtually all the U.S. sunflower
production.

Figure 1. Sunflower production has Increased rapidly in the U.S.,
with 1982 total acreage estimated at 4,724,000 acres. It fits
Indiana's soil and climatic conditions, but so far has not been
consistently competitive with corn and soybeans. Future profitability
will depend largely on the market price of sun oil.

Sunflower has gained in importance in the U.S. oil seed economy in
recent years. Total acreage in the four states mentioned was 2.9
million in 1983 and 4.5 million in 1982 (Table 1). These figures do
not include the non-oil sunflower production which ranged from
124,000 acres in 1983 to 315,000 acres in 1981 for the four major
producing states.

Table 1. Production of Oil Seed Type Sunflower in the Four Major
Producing States, 1981-83.

Indiana and Ohio each produced around 15,000 - 20,000 acres of
commercial sunflower in the late 1970's, but the acreage has since
declined. Most of the sunflower grown recently in the more humid areas
of the Midwest has been as a double crop after wheat.

The use of sunflower oil as a premium quality vegetable oil has
increased rapidly in the U.S. Several new processing plants designed
for crushing sunflower have been built in the North Dakota and
Minnesota area.

3. Is hybrid sunflower available?

Yes. Hybrid sunflower was made possible by the discovery of
cytoplasmic male sterility in 1968 and the restorer gene in 1970. The
switch to hybrids was rapid in the `70's. Most sunflower varieties
grown now are hybrids.

4. What are the advantages of hybrids?

Hybrids have four principal advantages over open pollinated
varieties: 1) they have approximately a 20 percent greater yield
potential; 2) they have better disease resistance, especially to rust,
downy mildew, and verticillium wilt; 3) they have a high degree of
self compatibility which reduces the need for bees for cross
pollination; and 4) they are more uniform in height and moisture
content at maturity which facilitates harvest.

5. Is sunflower adapted to Indiana soils and
climatic conditions?

Yes, there is ample evidence of good agronomic adaptation.

6. Then why haven't we grown sunflower in
Indiana?

We actually have had small commercial acreages in the state from
time to time. The problem has generally been profitability relative to
alternative crops (principally corn and soybeans) and marketing. If
we can solve the former, profitability, the markets will develop.

Our last cycle of interest in sunflower production was in 1979-81
when sunflowers were promoted for Indiana production by several seed
firms.

7. Is sunflower production profitable in Indiana?

It may be, but the real question is: Is it as profitable as corn and
soybeans in a given environment? There is no doubt that sunflower
yields have increased more rapidly than corn or soybean yields in the
last decade and that the gap in profitability has narrowed. Relative
profitability depends largely upon the assumed yield relative to
corn and soybeans in a given environment.

The U.S. average sunflower yield in 1983 was 1,041 pounds per acre;
the record U.S. average yield has been around 1,350 pounds. In the
humid midwest we can do better than this. Considering our inexperience
with the crop, however, it's doubtful that we can expect to average
more than 1,800 to 2,000 pounds per acre at the outset as a full
season crop.

8. What about Purdue yield trials with sunflower?

Several yield trials were conducted around the state during 1979-80
with hybrid sunflower varieties, comparing them to an equal number of
soybean varieties in the same environment, both as a full-season crop
and as a double crop planted after winter wheat. The results of
full-season trials are summarized in Table 2, and of double-crop
trials in Table 3. The full-season trials were planted with a
conventional tillage system. The double-crop trials were all planted
directly into wheat stubble without tillage. The four full-season
trials averaged 1,640 pounds per acre. The six double-crop trials
averaged 1,114 pounds per acre. These were harvested yields. In
addition, most of these trials sustained 10-20 percent bird damage,
with the Randolph County trial suffering an estimated 50 percent yield
reduction due to bird damage. In small, isolated blocks of sunflower
birds can harvest and shatter one-third to one-half of the seed in a
matter of days after the seeds begin to loosen in the head.

Based on these trials, with some experience and good management, it
is believed that full-season commercial sunflower yields of 2,000
pounds per acre are feasible in an average Indiana environment with
3,000 pound yields possible in the more productive environments
(Table 4). Double-crop sunflower yields should approach two-thirds of
the full-season yield for the same environment. When planted in May,
sunflower matures in mid-August in Indiana. Stalk quality
deteriorates rapidly under high ambient temperatures, and lodging
can be a serious problem if the seed is not harvested promptly.

9. Are there specific environments where sunflower might have a
relative advantage over soybeans?

The sunflower has an extensive taproot system which appears to do
relatively well under drought stress and/or low fertility
conditions. It also has potential for double cropping after winter
wheat, which we will discuss later.

10. Are weeds difficult to control in sunflower plantings?

The following herbicides are labeled for use with sunflower in
Indiana: Amiben, Lasso, Prowl, and Treflan. Amiben and Lasso are
labeled for both preplant incorporation and pre-emergence use. Prowl
and Treflan are labeled for preplant incorporation only. Amiben is
labeled for tank mix combinations with Prowl, Treflan, and
Lasso. Paraquat/Gramoxone is labeled for knock-down of existing annual
weeds in reduced tillage situations. Excellent weed control was
obtained with several of these combinations in recent trials. About
three weeks after emergence, sunflower plants form a dense canopy and
become very competitive with late emerging weeds.

11. How would sunflower fit in Corn Belt rotations?

There appear to be three major considerations for determining crop
sequence with sunflower: 1) control of volunteer sunflower, 2) control
of insects and diseases, and 3) effect of sunflower on the following
crop.

Crops following sunflower are often infested with volunteer
sunflower plants. In corn they may be controlled with and are
sensitive to applied or residual Atrazine. They may also be controlled
with 2,4-D or Banvel type materials. In soybeans they may be
controlled with Basagran applied post-emergence at the normal labeled
rate. Sunflower seed, with its high oil content, will not persist for
long periods in the soil.

The extent of the problem with sunflower insects and diseases is not
well known. Commercial acreage has not been extensive enough or
persisted long enough for diseases to become a serious problem. In
areas where large sunflower acreages are produced, most of the serious
diseases have been controlled by incorporating resistance in the newer
hybrids. There is an extensive list of diseases and insects which
infect sunflower. How serious these might be during the first few
years of production is not known. The sunflower headmoth has been
reported in northwestern Ohio where a small acreage of non-oil
sunflower is produced.

Sunflower has been considered to be a crop that is "hard" on the
soil. Research tests have not supported this claim. Where it is grown
sunflower is a deep-rooted, full-season crop that tends to remove
moisture from the soil later in the season than shallower-rooted,
short-season crops, such as small grain. This may have contributed
to lower yields following sunflower in dry land areas. In Indiana,
however, subsoil moisture is virtually always completely replenished
over the winter and this should not be a problem. Sunflower stalks
are easily broken up and incorporated into the soil after harvest.
They usually amount to less than 2 tons of dry matter per acre compared
with about 4 tons for corn.

12. What are the fertility requirements for sunflower?

The sunflower will grow on most soil types that are suitable for
corn or soybeans. They will produce better yields on fields with high
fertility levels and adequate moisture. They are not well adapted to
poorly drained soils which have water standing on them for extended
periods.

For phosphorus and potassium, fertility requirements are similar
to those for soybeans. The extensive taproot system of
sunflower may help utilize residual soil nutrients and aid in nutrient
uptake. Sunflower does remove as many nutrients as most other crops,
and these must be replaced somewhere in the rotation.

As far as nitrogen is concerned, farmers generally apply half to
two-thirds of that normally applied to corn-e.g., about 80-100
pounds per acre. One ton of sunflower requires 100 pounds of nitrogen
(soil and fertilizer) in the top 2 feet of soil. A 3,000-pound yield
requires 170 pounds of N. Micronutrients have not been shown to give
profitable responses. Sunflower seeds are sensitive to fertilizer
salts applied in the row.

13. What population is recommended?

Population rate is about the same as for corn-i.e., 20-25 thousand
plants per acre on silt loam and clay loam soils and about 15-20
thousand plants per acre on sandy or sandy loam soils. The sunflower
adjusts to thin populations by increasing head and seed size and to
excessive population by decreasing head and seed size.

For non-oil varieties it may pay to plant at a lower rate to qualify
for the higher price per pound paid for large seed. A 5,000-plant
reduction in population may not appreciably affect yield but will
significantly increase seed size.

For oil seed types the objective is to get maximum yield with no
regard to seed size. Medium to high populations produce seed of
higher oil percentage and bushel weight than low populations. Also,
high populations with smaller heads remain more upright and dry faster
than large heads. Low populations with larger heads usually lodge less
than high populations.

14. What is the optimum row width?

There seems to be a limited advantage to planting in narrow
rows. Minnesota reports that sunflower in rows 20-30 inches apart
out yielded those planted in rows 30-36 inches apart by about 10
percent. On the other hand, Tennessee reports little advantage to
sunflower in narrow rows.

It appears that sunflower behaves more nearly like corn than
soybeans in close configuration systems. Population is generally
held constant regardless of row widths. The favored row width is 20-30
inches, although rows as wide as 40 inches and as narrow as 14 inches
are grown.

15. What about planting depth?

Sunflower often takes longer to emerge than grain crops because of
the slow penetration of soil moisture through the hulls. The
seedlings, however, are vigorous and will germinate and emerge under
slightly cooler conditions than corn. The large seeded types can
emerge from rather deep placement of up to 3 inches in warm sandy
soils. Recommended planting depth for the oil seed types is 1-2
inches. The shallower depth should be used with cold, wet, and
fine-textured soils.

Sunflower can be planted with plate-type planters and suitable
plates (generally small, flat corn plates) or the finger pick up on
plateless planters or with air-type planters.

16. When should sunflower be planted?

A wide range of planting dates can be used for sunflower, but
highest yields are likely to be obtained when they are planted between
mid-April and mid-May in Indiana. The minimum temperature reported for
sunflower germination is 41 F. Temperature requirements for sunflower
germination and growth lie between those of small grains and
corn. Soil temperatures should be at least 45 before planting.
Sunflower seedlings have some frost tolerance until about the 6-leaf
stage. Sunflower also yields very well when planted in June or even
early July. In recent Indiana trials double-crop sunflower yields were
reduced by only one-third compared to May planting. This yield
reduction is comparable to soybeans and less than usually experienced
with corn or grain sorghum.

Remember that most breeding work has been done on hybrids adapted to
the Red River Valley of North Dakota and Minnesota. These are
short-season hybrids. Planting them late may actually assist
harvesting and drying since we would normally have a frost to aid in
plant desiccation.

17. What about seedbed preparation?

For full-season production seedbed requirements are comparable to
soybeans. The seedbed for sunflower should be moist, firm, and free
of weeds. Planting should occur immediately after the final
secondary tillage operation is performed.

18. What cultural weed control techniques are used?

Two methods of cultural weed control are commonly employed with
sunflower. Sunflower seedlings are strongly rooted and can be harrowed
several times, if necessary, during the 4-6 leaf stage.
Post-emergence harrowing should be done across rows and preferably on
a warm, clear day to assure the best weed kill and that the sunflower
plants are less turgid. The row cultivator is also commonly used as
necessary depending on the weed situation in the field.

Lateral sunflower roots are shallow and can easily be damaged by
cultivating too deep and too close to the plants. It is generally
suggested that sunflower not be cultivated after the plants are 12
inches tall. Hilling at the last cultivation covers small weeds in the
row and may help reduce root lodging. In general, cultivation should
be no closer to the row center than the leaf spread of the plants.

19. Are birds a problem?

Sunflower, owing to its head structure, is easily damaged by
birds. The seeds are exposed and the head serves as a perch during
feeding. Birds are often a problem when only small acreages of
sunflower are present in a given area. Greatest losses are from flocks
of starlings and red winged blackbirds.

Control is difficult. Various scaring devices such as the gas
exploder may be effective if employed early. Field application of
Avitrol, a fright-producing repellent, is registered for use in
sunflower and field corn.

20. What special equipment is required for
sunflower production?

Sunflower is produced with conventional corn and soybean equipment,
except that a sunflower head attachment Is added to the grain platform
on the combine for harvesting. In lieu of a sunhead, a John Deere
soybean row header may be used.

A corn head or conventional grain table are not considered suitable
because of excessive harvest losses. Tennessee reports harvest losses
at the header and reel with the conventional small grain platform
of 46 percent, but only 5 percent with the Willmar sunhead attachment.
Processing losses within the combine were only 2 percent.

21. How is sunflower harvested?

It is harvested with a conventional combine, grain platform, and a
sunhead attachment.

The sunflower is physiologically mature when the back of the head
has turned from green to a light lemon yellow and the bracts are
turning brown. This usually occurs 30-45 days after bloom depending on
temperature during the maturation period. Desiccants, if used, are
applied at physiological maturity (25-30 percent seed moisture) and
may allow an earlier harvest by permitting the head, stalk, and leaves
to dry more rapidly. A killing frost will also facilitate drying in
the northern areas.

The sunflower stalk tends to deteriorate rapidly, and lodging as
well as birdfeeding may be a problem if the sunflower must remain in
the field long after maturity.

Combining usually begins at 18-20 percent moisture. Most electric
testers won't check sunflower; however, Dickey-John offers for their
tester a special chart and ring adapter (for weight) for sunflower
that is reasonably accurate.

Sunflower thrashes relatively easily. The better sunheads have a
stalk-walker which pulls the sunflower stalks and weeds down so that
only the head is fed into the combine. This is important to keep trash
levels low. The cylinder speed should be as low as possible (generally
300-450 RPM) and still thrash the seeds out of the head. Excessive
speed causes considerable dehulling.

When the crop is dry (10 percent or less), the concave should be set
wide open. It is usually possible to set the cylinder concaves and
cleaning shoe to obtain less than 5 percent trash dockage. Under wet
conditions, it may be necessary to use higher cylinder speeds and
closer concave settings even though foreign material in the seed
increases. The long gathering pans extending ahead of the cutter bar
are used to salvage shattered seed. The width of the gathering pan
varies. Narrow 9-inch pans spaced on 12-inch centers can operate on
any desired row spacing, while wider and more efficient 30-40-inch
spaced pans are limited to a fixed row width.

For estimating harvest losses, a count of 10 seeds per square foot
on the ground means that the grower is losing about 100 pounds of seed
per acre.

22. Is drying required for sunflower?

Generally, yes. Seed should be below 12 percent moisture for
temporary storage and down to 9 percent for longtime
storage. Minnesota grade standards allow a maximum moisture content of
10 percent for grade 1 for both oil seed and non-oil seed types.

Harvesting sunflower with high moisture content normally results
in high yields, less bird damage, and less head dropping and
shattering. In a wet fall, drying would be mandatory in Indiana
where moisture content could remain over 20 percent until very late in
the season. Sunflower dries very easily compared to corn and
soybeans; and operators accustomed to drying these crops may tend to
overdry sunflower. The large seed allows air to pass easily. Because
of the low bushel weight, relatively small quantities of moisture are
removed.

Most dryers are designed for corn and small grains which require
higher moisture removal. For example, drying corn from 25 percent to
15 percent moisture will remove 6.6 pounds of moisture per bushel of
volume. Drying sunflower from 20 percent to 10 percent moisture
removes only about 3.0 pounds of moisture per bushel. Unheated air is
often adequate for drying sunflower.

Drying temperatures of 160 up to 220 F. do not seem to adversely
affect oil yield or fatty acid composition. Sunflower for seed should
not be dried over 110 F.

The threat of fire is of high concern during the drying process. An
oily fuzz rubs off sunflower hulls as the seed is moved. These hairs
or fibers ignite when drawn through the drying fan in open
flame. Unless they burn themselves out before hitting the hot
sunflower seed, a fire hazard is present. Drying equipment should not
be left unattended with sunflower.

Seed should be cleaned for storage and large pieces of head and
stalk removed as this is often the highest moisture
fraction. Sunflower should be cooled down for over-winter storage to
prevent moisture migration the same as with shelled corn.

23. Can sunflower be double-cropped successfully after winter wheat
in Indiana?

Yes, the no-till double-crop trials conducted recently indicate that
sunflower can be successfully grown as a second crop after winter
wheat in virtually all areas of Indiana. The ability to plant later
and still mature before frost is a key advantage of double-cropped
sunflower over soybeans. Currently, we have no viable wheat-soybean
double-crop System for the northern third of Indiana. In this area
wheat matures later, after July 1, and the first fall frost is
earlier, around October 1-5 on average. Double-crop soybeans are
usually high risk when there are less than 90 frost-free days after
wheat harvest.

As mentioned, sunflower suffers no greater yield reduction than
soybeans for delayed planting. If sunflower has a unique niche in the
state it is probably for double cropping in the northern half of
Indiana. Planting can be as late as about July 15 and still produce a
reasonable yield. The frost tolerance of sunflower makes it the
preferred candidate for double cropping under short season or delayed
planting conditions. A fall temperature of about 24 F. is required to
kill sunflower, whereas soybeans are usually killed at temperatures of
29 to 31 F.

The field research with double-crop sunflower to date suggests the
following observations:

1) Sunflower can be safely planted 10 to 14 days later than
soybeans as a double crop.

2) The no-till management System utilized for producing soybeans
after wheat is adaptable to sunflower. The only difference noted is
that sunflower requires slightly more residual soil moisture for
prompt germination. Once established, sunflower has drought
tolerance that is equal to or better than soybeans.

6) The normal yield range for double-crop sunflower should be 1,000
to 1,500 pounds per acre with good management. Yields of a ton or more
can be produced on occasion after winter wheat in southern Indiana
with good stands, moisture, fertility, and weed control.

24. How do you go about marketing sunflower in Indiana?

Local markets currently are very limited but would develop if a
commercial sunflower acreage persists and grows to produce enough
volume to interest exporters. A logical market would be through the
Great Lakes or the Ohio River for the export market. The Pillsbury
Company at Cincinnati, Ohio, has purchased oil-type sunflower for
barge shipment to New Orleans.

The nearest major market for the oil-type sunflower is Duluth,
Minnesota. The Cargill Terminal at Tipton has purchased sunflower
for a backhaul to Duluth, paying about 2 cents under the Duluth
market. Several local elevators in northern Indiana have also
expressed interest in buying sunflower, but this should be verified
locally.

If sunflower is grown without a commitment from a local market, then
a producer should be prepared to deliver sunflower over rather long
distances to find a suitable market. Remember, because of the low
bushel weight, sunflower is hauled in semi's with higher-than-normal
cargo boxes in order to obtain a normal weight load.

A limited market for the non-oil type exist in northwestern Ohio and
north central Illinois. There are special requirements, however, for
producing and cleaning the non-oil type, and these should be verified
before planting.

25. Is sunflower competitive with corn and soybeans under Indiana
conditions at this time?

In my opinion, generally not as a full-season crop in most Indiana
environments, but they may still be profitable, and the gap in gross
return per acre has narrowed substantially in the last
decade. Sunflower double cropped after winter wheat offers the best
potential, especially for the northern one-third of Indiana where
soybean double cropping is difficult.

26. What's your best guess on comparable yields and returns per acre?

Table 4 shows my estimate of comparable yields and returns for
Indiana for full-season sunflower. For double-crop soybeans and
sunflower, reduce the estimated yield and returns by about one-third,
and add the projected value of the wheat crop.

27. How does the cost of production compare with corn and soybeans?

The cost of growing sunflower would be slightly more than soybeans,
but less than corn. As a rule of thumb, consider the cost to be the
same as you would have for soybeans plus about $15.00 per acre for
nitrogen (100 pounds at 15 cents) plus the amortized cost of a sunhead.

28. What does the future look like for sunflower?

Sunflower produces a valuable product, and sunflower production for
both export and domestic use has expanded rapidly in the U.S. in the
last decade. Production has been concentrated in the northern areas
where sunflower has a relative advantage and alternate crops such as
corn, soybeans, and winter wheat are less attractive. Whether
sunflower can successfully compete in Corn Belt areas such as
Indiana must still be determined.

There is no other crop in the U.S. that produces as many pounds of
oil per acre as sunflower. The oil is the most valuable part of the
sunflower: it normally sells for a premium of 2-8 cents per pound over
soybean oil. Thus, profitability and the price of sunflower depends
largely on the market price of sun oil.

New products from sun oil have recently been introduced into the
oilseed market. These include Promise margarine, and Puritan, Sunlite,
and Sunflo salad and cooking oil. Sun oil is higher in polyunsaturates
than any other vegetable oil grown in the U.S. except safflower oil.

Table 5 compares the oil content and the fatty acid content of the
major U.S. grown vegetable oils. Sun oil strikes a rather ideal
compromise between the polyunsaturated fatty acids and stability for
most edible uses. It contains only trace amounts of the undesirable
linolenic fatty acid. Because of its stability and high smoke point,
it is gaining favor with the fast food industry.

U.S. processors ordinarily do not dehull sunflower during oil
extraction; thus the hulls, which account for 22-28 percent of seed
weight, remain with the meal. Primarily for this reason. sunflower
meal is less valuable than soybean meal. Its crude protein content is
lower-only about 30 percent (prepress solvent process) compared to 49
percent for soybeans (dry matter basis). It also has a higher fiber
content because of the hulls (26 percent vs. 8 percent).

Sunmeal is also low in the essential amino acid,
lysine. Digestibility is good and no toxic compounds have been found
in sunmeal. In complete mixed feeds it is usually blended with other
oilseed meals. Sunmeal is best suited for ruminant rations because of
the high fiber and low lysine content.

The future of sun oil for use in salad and cooking oils, margarine,
and shortening appears bright. It competes with soy oil in most end
products.

29. Are there any good references on sunflower production?

An excellent reference is available from North Dakota State
University, Fargo, North Dakota 58102. Ask for Ext. Bulletin 25
(revised July 1978) entitled Sunflower Production and Marketing. The
cost is $3.00.

Reference to products in this publication is not intended to be an
endorsement to the exclusion of others which may he similar. Persons
using such products assume responsibility for their use in accordance
with current directions of the manufacturer.

Rev 11/84

Cooperative Extension work in Agriculture and Home Economics, state of
Indiana, Purdue University, and U.S. Department of Agriculture
Cooperating; H.A. Wadsworth, Director, West Lafayette, IN. Issued in
furtherance of the acts of May 8 and June 30, 1914. The Cooperative
Extension Service of Purdue University is an affirmative action/equal
opportunity institution.